Medical image processing apparatuses exist for displaying three-dimensional image data collected by medical image diagnostic apparatuses. The medical image diagnostic apparatus herein includes an X-ray Computer tomography (CT) apparatus or Magnetic resonance Imaging (MRI) apparatus, X-ray diagnostic apparatus, ultrasound diagnostic apparatus, etc.
(Virtual Endoscopy: VE) is one method of displaying medical images based on three-dimensional image data obtained using such a medical image diagnostic apparatus.
VE is capable of displaying VE images in which an object located close to a viewpoint is displayed larger while an object located far from the viewpoint is displayed smaller. Furthermore, because VE is capable of arbitrarily setting the position or the direction of the viewpoint, regions impossible to be observed using an endoscope may also are displayed. In general, VE displays images by automatically shifting the viewpoint from the trajectory of a three-dimensional core line passing the lumen of a tubular structure such as a preliminarily extracted large intestine or esophagus. Such a method of displaying images is referred to as a fly through display. In an actual diagnosis, for example, an operator makes a diagnosis by observing VE images being updated while the viewpoint is moving in the fly through display.